FLG and asthma: Our finding that a family history of eczema is a stronger risk factor than a family history of other atopic diseases is compatible with, for example, the ALSPAC study, where parental eczema was regarded as a better marker than parental asthma or hay fever.27 In fact, a Danish twin study found that genes accounted for 82% of individual susceptibility, while non-shared environmental factors accounted for 18%.28 Recently, it has been demonstrated that loss-of-function mutations in the filaggrin gene predispose to eczema.